A person is no different from an entity the trust level is the same or even worse. A distributed set of people/entities like a federation is the same as a group of Spark operators where only one honest one is enough. Keep in mind that Spark operators don't mean they are run by Spark. What you mention that could help is that making it easy for someone to run the operator sw and join and maybe make some standard so that you can have many different state chains but all compatible, don't know if it's possible.